Implantable cardioverter-defibrillators (ICDs) have been developed that employ detection algorithms capable of recognizing and treating ventricular tachycardias and ventricular fibrillation. Detection algorithms are also being developed to recognize and treat atrial tachycardias and atrial fibrillation. In general, ICDs are designed to treat such tachycardias with antitachycardia pacing and low-energy cardioversion shocks in conjunction with back-up defibrillation therapy. These ICDs monitor the heart rate and the onset of the arrhythmia by sensing endocardial signals and determining when the heart is in need of either cardioversion to treat a given tachycardia or of defibrillation to treat a fibrillation condition.
Certain ICDs have been designed with dual chamber sensing capabilities to detect and analyze both ventricular and atrial endocardial signals. This increase in cardiac signal input to the ICD has provided an opportunity to determine the origin and the nature of atrial and ventricular tachyarrhythmia, and to reduce the frequency of inappropriate therapy being delivered to an implant patient.
Under certain conditions and testing, it may be desirable to temporarily disable, or otherwise alter, the normal antitachyarrhythmia detection and response programming of an ICD, such as during ICD implant, for example. It is imperative that any antitachyarrhythmia detection and response programming that is temporarily altered for purposes of conducting certain cardiac testing be returned to nominal operating condition at the conclusion of such testing.
For the reasons stated above, and for other reasons stated below which will become apparent to those skilled in the art upon reading the present specification, there is a need in the art for improved cardiac testing techniques, particularly during device implant, that provide for the alteration of standard atrial and ventricular arrhythmia detection and response programming of the device. There exists a further need for such techniques that provide failsafe assurance that any antitachyarrhythmia therapy programming that is altered for a particular cardiac test be returned to nominal operation condition at the conclusion of such testing. The present invention fulfills these and other needs, and provides advantages over prior art implementations.